Tapping and drilling machine



April 18, 1933. H. KIND 1,904,375

TAPPING AND DRILLING MACHINE Filed Nov. 18, 1929 2 Sheets-Sheet 1 April18, 1933. F. H. KIND 1,904,375

TAPPING AND DRILLING MACHINE Filed NOV. 18, 1929 2 Sheets-Sheet 2hpemfor Patented Apr. 18, 1933 UNITED STATES PATENT OFFI'CE FREDERICK H.KIND, OF MANITOWOC, WISCONSIN, ASSIGNOR TO W. GATERMAN MIG. (JO-,0!MANITOWOC, WISCONSIN TAPPING AND DRILLING MACHINE Application fledNovember 18, 1929. Serial No. 408,040.

This invention pertains to tapping and drilling machines, and moreparticularly to the former. a p

The invention has primarily for its object to materially simplify andotherwise improve the structure disclosed in Letters Patent No.1,403,170, issued January 10, 1922, which provides gear mechanism andpositive actuated dogs for reversing the direction of rotation of thetool spindle, when the tool is subjected to predetermined torsionalstress, due to hard spots encountered in the work material.

In general, the foregoing object is accomplished by the elimination ofreverse gear mechanism and the provision of a novel type of automaticclutch, which not only releases the spindle when a predeterminedtorsional stress is placed upon the tool, but also effects the desiredreversal of rotation of the spindle to release the tool.

Incidental to the foregoing, a more specific object resides in theprovision of a novel type of clutch for operatively connecting anddisengaging the tool spindle from the driving mechanism, and which isautomatically released when the tool is subjected to a predeterminedtorsional stress, and which upon release, will cause an automatic,intermittent reversal of rotation of the spindle through a cammingaction between the clutch elements and the spindle, without reversal ofthe driving element.

A further object resides in the provision of a mechanism of theforegoing character which eliminates complicated electric actuating and,timing mechanism, the timing of reversal o rotation of the spindlebeing controlled by the speed of the spindle drive mechanism.

Another important object of the present in- 40 vention resides in theprovision of a mechanisin of the foregoing character which will operatein both directions, thus functioning upon Withdrawal of the tool, aswell as upon the feeding operation.

With the above and other objects in view,

which will appear as the description proceeds, the invention resides inthe novel construction, combination, and arrangement of partssubstantially as hereinafter described and more particularly defined bythe appended claims, it being understood that. such changes in theprecise embodiment of the herein disclosed invention may be made as comewithin the scope of the claims. a

In the accompanying drawings is illustrated one complete example of thephysical embodiment of the present invention constructed according tothe best mode so far devised for the practical application of theprinciples thereof.

In the drawings, Figure 1 is a vertical sectional view through the headof a machine constructed in accordance with the present invention;

Figure 2 is a fragmentary detail view of 5 the clutch mechanism betweenthe drive and tool spindle.

Figure 3 is a detail section through the clutch taken on the line 33 ofFigure 4;

' Figure 4 is a vertical section taken on the line 4-4 of Figure 3; and

Figure 5 is a diagrammatic view illustrating the intermittent reversalaction upon the spindle.

Referring now more particularly to the accompanying drawings, in whichthe invention is shown ,as applied to a conventional type of drillingand tapping machine, the numeral 1 designates ahead in which a portionof the actuating mechanism is housed.

f Slidably mounted within the head 1 is a tool spindle 2 for receivingeither a drill or tap (not shown), which may be secured within thespindle in any manner well known to those skilled in the art. Thespindle 2 is journalled inanti-frictional'bearings 3 carried by aslidable sleeve 4, which sleeve is provided at one side with rack teeth5 engaged by a feed pinion 6, the pinion 6 beingmounted upon a shaft 7provided with the usual hand lever (not shown), for manually feeding thespindle toward the work.

11 addition to the manual feed described, the spindle may beautomatically fed toward the work by means of a piston 8 secured to itsupper end and mounted within a pneumatic cylinder 9.

The driving mechanism for the tool spindle comprises a drive shaft 10journalled in antifrictional bearings carried by a housing mountedwithin the head 1 and designated in general by the numeral 11. The driveshaft 10 is operatively connected with a bevel drive pinion 12, whichmeshes with bevel gears 13 carried by the cones 14 and 15, the latterbeing journalled upon anti-frictional bearings 16 mounted uponstationary parts of the housing 11. Cooperating with the cones 14 and 15are a pair of cone clutches 17 secured upon a shaft 18, which shaft hasa vertical reciprocative movement effected by a piston 19 secured to itsupper end and mounted within the pneumatic cylinder 20. Pressure fluidentering the cylinder 20 through a supply ,pipe 21 will force the piston19 downwardly to effect engagement between the lower cone clutch 17 andthe cone 15, while the upper cone clutch 17 engages the cone 14 throughthe action of a spring 22 engaging the lower end of the shaft 18.Obviously, the pressure fluid employed to effect depression of thepiston 19, and operative engagement between the lower clutch 17 and thecone 15, may be utilized for actuating the piston 8 to effect feed ofthe tool spindle 2, the cylinders 9 and 20 being connected through thecommunicating pipe 23. V 4

Drive of the spindle 2 is accomplished through a gear train, includingthe pinion 24 keyed on the shaft 18 and engaging an idler ggar 25 which,in turn, meshes with the gear \Vhile a specific form of mechanism foreffecting the drive and feed of the tool spindle has been described inconsiderable detail, it

is to be understood that such mechanism is more or less conventionaland, therefore, forms no specific part of the present invention, otherthan in the general combination as hereinafter embodied in the claims.

As set forth in the objects, the present invention consists primarily inthe novel method of effecting an operative connection between thespindle drive and the spindle.

In the present instance, this is accomplished .28 of the sleeve 28. Asbest shown in Figure 3, the head 28 is provided with a plurality ceptionof the ball clutch members 31, which in turn are carried in the radialslots 32 formed in the annular flange 26'. Obviously, as the balls 31are forced into the recess 30, operative engagement between the gear 26and the sleeve 28 will be effected, which in turn transmits rotation tothe spindle 2, due to the fact that the sleeve 28 engages the squareportion 27 of the spindle.

Normally retaining the balls 31 in operative engagement between the gear26 and the sleeve 28 is a cup 33 provided with an internal flange 34intermediate its upper and lower ends, which flange is engaged by thesprings 35 mounted in spaced recesses 36 provided in the annular flange26'. The cup 33 is journalled upon anti-frictional bearings 37 which inturn are carried by a sleeve 38. As best shown in Figure 4, the interiorof the lower lip of the cup 33 is bevelled at 39 to engage e the balls31, and to relieve wear upon t cup, the interior lower wall beingprovided with a hardened sleeve 40.

Engaging the sleeve 38 is a spanner arm 41, the fulcrum end of which isconnected to an eccentric pin 42 by a link 43. As best shown in Figure2, the eccentric pin 42 is carried by a rotatably adjustable shaft 44journalled in the head 1, and provided with a squared head 44' at itsouter end for reception of a handle or suitable tool. The arm 41 isretained within the head 1 by means of a locking screw 45 enga ed in anannular recess 46 formed in the shaft 44; The free end of the spannerarm 41 is connected with a stationary portion of the head by means ofv acontractile spring 47, and the same is cushioned by a spring 48 carriedon the stud 49. From the foregoing description taken in connection withthe drawings, it is believed that the operation of the spindle drive andfeeding mechanism will be quite apparent, in that the main drive istransmitted through the shaft 10 to the drive pinion 12, and from thegears 13 to the clutches 14 or 15, which are selectively engaged byeither of the cones 17 to effect rotation of the shaft 18 in oppositedirections.

Actuation of the piston 19 serves to engage of spaced semi-sphericalrecesses 30 for regear 26 and the sleeve 28 is maintained until suchtime as the tool is subjected to a predetermined torsional stress, asoccurs when the operative connection with the gear 29,cansing the balls31 to rotate along the outer periphery of the head 28', and again efiectoperative connection between the gear 26 and the sleeve 28, as they dropinto the following recesses. During the latter action, as the center ofthe balls 31 pass over the rear edge of the recess 30, the force exertedupon them by the springurged cup 33 will cause the balls 31 to effect areverse relative movement between the gear 26 and the head 28' throughthe camming action of the balls 31 upon the rear edges 31' of therecesses 30, thus tending to break the tool loose from any bind in thework material. This action is best illustrated in Figure 5. Obviously,until such time as the torsional stress upon the tool is relieved, theballs 31 will continue to rotate around the head 28', intermittentlydropping into the recesses 30, each time repeating the reverse cammingaction upon the head tobreak the tool loose.

Heretofore complicated means have been employed for timing the reverserotation of the spindle to break the tool loose and, therefore,particular attention is here directed to the fact that such mechanism isentirely eliminated, in that the action of the novel type of clutch isentirely automatic and, therefore, the intermittent rotation of thespindle is controlled entirely by the speed of rotation of the gear 26,and the spindle will only be reversely rotated a minimum number of timessuflicient to break the tool loose and overcome the excessive torsionalstress upon the same.

Here it is im ortant to note that the clutch between the gear 26 and thesleeve 28 will function equally as well in both directions of drive ofthe gear 26. Thus, should the tool be subjected to excessive torsionalstress, upon withdrawal of the same from the work the clutch willfunction in the manner as heretofore described, to disengage the spindlefrom the drive until such time as the stress upon the tool is relieved.

Naturally, when light drills or taps are being used, it is desired torelease the spindle drive when the tool is subjected to lightertortional stress than in instances where heavy tools are used.

In the drawings, the clutch is set to function in connection with themaximum size tool, and referring particularly to Figure 2, it will benoted that the eccentric pin is adjusted to its lowermost position,which lowers the fulcrum point of the arm 41 and thus increases thetension exerted upon the cup 33 and the balls 31. Where lighter toolsare employed,.-the shaft 44 is rotated by means of a handle or tool (notshown) fitted on the head 44', which action raises the fulcrum end ofthe lever 41, and also the cup 33. Naturally, due to engagement of thetapered lip 39 of the cup 33, releasing action will take place morereadily than when the cup is adjusted to its lowermost position, due tothe fact that shorter movement is required to cam the cu upwardlysufliciently to permit release 0? the clutch balls. The springs 35,engaging the internal flange 34 of the cup 33, serve to take up playhetween the cup and spanner arm 41, thus insuring a sensitive action ofthe clutch. From the foregoing, it will be readily seen that anexceedingly simple and efiicient mechanism has been provided whichautomatically controls the drive of the toolspindle to release thespindle when the tool encounters excessive torsional stress, and toreverse rotation of the spindle sufiiciently to break the tool loosefrom any bind in the work material, thus preventing breakage of toolsand eliminating the necessity of skilled labor.

I claim:

1. In a machine of the character described,-

a tool carrying spindle, driving means for rotating the spindlecomprising an annular member carried by said spindle and provided with asemi-spherical pocket in its periphery, a driven sleeve surrounding saidannular member and provided with an opening for alignment with saidpocket, a ball normally positioned within said opening and pocket, and aspring-urged sleeve having an internallytapered face for engagement withsaid ball.

2. In a machine of the character described, a tool carrying spindle,driving means for retaining the spindle comprising an annular membercarried by said spindle and pro- 1 vided with. spaced radialsemi-spherical pockets, a driven sleeve surrounding said annular memberand provided with openings for alignment with said pocket, a shiftablesleeve having an inner peripheral tapered face for engagement with saidballs, and a spring-urged spanner connected with said shiftable sleeveto urge the same into engagement with said balls.

3. In a machine of the character described, a tool carrying spindle,driving means for retaining the spindle comprising an annular membercarried by said spindle and provided with spaced radial semLsphe'ricalpockets, a driven sleeve surrounding said annular member and providedwith openings for alignment with said pocket, a shiftable sleeve havingan inner peripheral tapered 4 mew face for engagement with said hells,e. spring-urged spanner connected with snid shiftable sleeve to urge thesame into engagement with sniol bells, and means con- 5 nected with saidspanner for varying the tenion thereon.

In testimony that I claim the ioregoing 1 have hereunto set my hend'etManitowoc, in the county of Manitowoc and State of Wisconsin.

' FREDERICK H. KIND.

